const promise = new Promise((resolve, reject) => {
    console.log(1);
    setTimeout(() => {
        console.log('timerStart');
        resolve('success');
        console.log('timerEnd');
    }, 0);
    console.log(2);
});

promise.then((res) => {
    console.log(res);
});

console.log(4);

// 1 -> 2 -> 4 -> timerStart -> timerEnd -> success